Power transformer output voltage ?

Hi !!

i wanna modified my G7 psu like duka
but my two 470µF are 200v only....

- i wanna know if i use a 220:9 -> 12:220
which voltage i found at the 12:220 output
when the psu work alone ?
- Do i risk to blow my capacitors ?


how to calculate this value ?

i have measure 11v at the output of my 220:9 transformer
when it just connect to my 220~ ?

So if we put 12v in a 12:220 transformer
we don't have 220 at the output ??


sorry for this newbie question, but after few search
i don't find a clear answer :?

The wire in the primary windings is thin, so the voltage is not very stable. When you connect 11V to the 12V winding you will most likely get more than 220V at the primary - without a load. The voltage will drop (a lot) when loaded. But you need 350V caps minimum - 385 or 400V would be better.

The unloaded DC voltage will be Vrms * sqrt(2). Just connect the transformer and measure the AC voltage you get out.

Best regards,

Mikkel C. Simonsen

thanks